content: /*
   * Copyright 2017 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.reactive4javaflow.impl.consumers;
  
  import hu.akarnokd.reactive4javaflow.FolyamSubscriber;
  import hu.akarnokd.reactive4javaflow.impl.*;
  import hu.akarnokd.reactive4javaflow.impl.util.SpscCountDownLatch;
  
  import java.lang.invoke.*;
  import java.util.concurrent.*;
  
  public abstract class AbstractBlockingConsumer<T> extends SpscCountDownLatch implements FolyamSubscriber<T> {
  
      T item;
      Throwable error;
  
      Flow.Subscription upstream;
      static final VarHandle UPSTREAM = VH.find(MethodHandles.lookup(), AbstractBlockingConsumer.class, "upstream", Flow.Subscription.class);
  
      public AbstractBlockingConsumer() {
          super();
      }
  
      @Override
      public final void onSubscribe(Flow.Subscription subscription) {
          if (SubscriptionHelper.replace(this, UPSTREAM, subscription)) {
              subscription.request(Long.MAX_VALUE);
          }
      }
  
      protected final void cancel() {
          SubscriptionHelper.cancel(this, UPSTREAM);
      }
  
      public final T blockingGet() {
          if (getCount() != 0) {
              try {
                  await();
              } catch (InterruptedException ex) {
                  cancel();
                  throw new RuntimeException(ex);
              }
          }
          Throwable ex = error;
          if (ex != null) {
              if (ex instanceof Error) {
                  throw (Error)ex;
              }
              if (ex instanceof RuntimeException) {
                  throw (RuntimeException)ex;
              }
              throw new RuntimeException(ex);
          }
          return item;
      }
  
      public final T blockingGet(long time, TimeUnit unit) {
          if (getCount() != 0) {
              try {
                  if (!await(time, unit)) {
                      cancel();
                      throw new TimeoutException();
                  }
              } catch (InterruptedException | TimeoutException ex) {
                  cancel();
                  throw new RuntimeException(ex);
              }
          }
          Throwable ex = error;
          if (ex != null) {
              if (ex instanceof Error) {
                  throw (Error)ex;
              }
              if (ex instanceof RuntimeException) {
                  throw (RuntimeException)ex;
              }
              throw new RuntimeException(ex);
          }
          return item;
      }
  }
  